Corner construction for membrane sealed cartons

ABSTRACT

An arrangement is provided for an improved leak-proof corner structure for sealed cartons, having a separate membrane material, heat sealed or otherwise adhesively secured to the outfolded end flaps of the erected carton, prior to the infolding thereof, and having in combination with the usual &#39;&#39;&#39;&#39;tufted&#39;&#39;&#39;&#39; corners, raised contact areas or lands at each corner for enhancing the engagement with the sealing membrane.

United States Patent 11 1 Young et al. 1 Sept. 4, 1973 [54] CORNER CONSTRUCTION FOR 2,886,231 5/1959 Benzon-Petersen 229/37 R X MEMBRANE SEALED CARTONS 3,040,958 6/1962 Hagan 229/37 R 3,098,599 7/1963 Hagan....... 229/37 R Inventors: Chauncey g, Louis; William 3,473,723 10/1969 Bolling et a1... 229/37 R H. Watson, Affton, both of M0. 3,656,682 4/1972 Guiliani 229/48 T [73] Assignee: Rexham Corporation, New York,

NY. Primary ExaminerDavis T. Moorhead Attorney-Hubert T, Mandeville, Michael A. [22] Filed: Jan. 5, 1972 Comma et a].

[21] Appl. No.: 215,608

[57] ABSTRACT [52] US. Cl. 229/37 R An arrangement is provided for an improved leak- [51] Int. Cl 865d 5/02 proof comer structure for sealed cartons, having a sep- [58] Field of Search 229/37, 48 T ra m mbrane material, heat sealed or otherwise adhesively secured to the outfolded end flaps of the [56] References Cited erected carton, prior to the infolding thereof, and hav- UNITED STATES PATENTS ing in combination with the usual tufted corners, 3 126 I43 3/1964 Hagan 229/37 R raised contact areas or lands at each comer for enhanc- 3:481:52? 12/1969 Jacke .1:II:I.::..::::::::...::.... 229 37 R the engagement the membrane 2,795,364 6/1957 Benzon-Petersen 229/37 R 8 Claims, 3 Drawing Figures PATENIEU E 4 I97 FIG, 2

FIG.

CORNER CONSTRUCTION FOR MEMBRANE SEALED CARTONS Generally speaking, this invention relates to an arrangement for enhancing the leak-proof characteristics of the corner structure for sealed cartons, utilizing a separate membrane seal which is applied to the erected cartons on the ends thereof, while the end flaps for such a carton are still in their outfolded stage. More particularly, this invention relates to an arrangement which utilizes prior art tufting concepts, as generally shown and described in U. S. Pat. Nos. 2,795,364 and 2,886,231, in combination with an enhanced membrane-engaging structure in the form of raised contact areas at each corner of the erected carton, which contact areas together with a slight tufting effectively resiliently engage the sealing membrane, so as to provide completely leak-proof corner structures at each end of the carton.

As is known, paperboard cartons have been used increasingly in recent years for the packaging of liquid and powder type material, mainly because of the development of a variety of resins which can be utilized for the lining and sealing of the cartons, so as to prevent leaking of the contents. However, certain difficulties have arisen with this use of paperboard cartons in that, although the paperboard cartons have generally been effectively sealed against leakage of their contents, and the paperboard itself has been made moisture impervious, there may be certain weakness during rough handling, because of the required folding structure of the ends of the cartons after insertion of the materials being packaged.

In the usual so-called air-tight, leak-proof paperboard carton construction, cartons are utilized of rectangular or square cross-section and have their opposite ends tightly sealed by an impermeable safety shield" membrane adhered to the carton flaps while they are in their outfolded condition. Typically, the membrane material and/or the inner surfaces of the flaps themselves to which the membrane is adhered are adhesively thermoplastic. In addition, the strength and vapor barrier properties of these drumhead" cartons are of a laminated paperboard structure, in which the paperboard is laminated with foil and coated with a resin, such as polyethylene, for example.

Whereas the tufted corner arrangements described in the above-mentioned patents and further recent developments have enhanced the leak-proof qualities of cartons of this type, particularly with respect to their condition as initially. constructed and sealed, these constructions have not always proved entirely satisfactory under less than optimum conditions. As will be understood, mass distribution of liquids and powders in cartons of this type involves substantial handling, causing the breakdown of the leak-proof characteristics of such construction, particularly at the weakest point thereof which are the corners, because they are subjected to crushing pressure during handling and shipping.

This invention, by contrast, utilizes a raised or area contact arrangement at each of the four comers of the carton at each end thereof for an enhanced frictional area contact engagement of the carton structure in the vicinity of the comers thereof with the sealing membrane applied thereto. This is achieved by the use of interruptions in the usual score line between the various wall panels of the carton and the end flaps therefor. The interruptions are in the form of a pair of angled score lines disposed in the vicinity where ordinarily the score line between the wall panels of the carton and the end flaps thereof would intersect with the vertical score lines dividing the various wall panels. Each of the angled score lines forming the pair extend at an angle in the vicinity of said intersection from the main line dividing the wall panels of the carton with their respective end flaps and intersect each other in the axis of the vertical score lines between the various wall panels of the carton.

In addition, with this arrangement, the cuts dividing the various end flaps end at a point spaced from the intersection of the pairs of angled score lines in order to provide a tufted arrangement at the corners of the carton in combination with the raised contact areas provided herein. Therefore, upon squaring of the carton and outfolding of the end flaps preparatory to application of the sealing membrane, a tufted, raised portion is provided at each corner of the carton.

- Because of the arrangement of the intersecting pairs of score lines, small additions or appendages are provided on adjacent wall panels of the carton in the area immediately adjacent the corners therof, which additions, upon erection of the carton and the outfolding of the end flaps thereof, curve slightly outwardly from the interior of the carton. Therefore, upon application of the sealing membrane, there is a slight upward spring action given by the raised, slightly outwardly curved contact areas or lands upon the downwardly pressed application of the sealing membrane. Accordingly, there is enhanced sealing engagment with the membrane, which serves to provide ultimately appropriate leak-proof sealing of all of the corners of the carton. Furthermore, because of this enhanced pressure engagement, failure in subsequent handling and distribution of the cartons is substantially avoided.

Thus, it is one object of this invention to provide enhanced leak-proof, membrane-sealed drumhead cartons for holding liquid or powdered materials. In addi tion, it is a further object of this invention to provide such cartons in which sealing engagement at the corners of the cartons with the membrane seal is provided with an upward resilient action during application. Furthermore, it is an object of this invention to provide for such cartons which substantially avoid failure of the sealing properties thereof upon subsequent handling and distribution.

With the foregoing and additional objects in view, this invention will now be described in more detail, and

otherobjects and advantages thereof will be apparent from the following description, the accompanying drawings, and the appended claims. In the drawings:

FIG. 1 is a partial, plan view of a carton blank from which an endsealed carton embodying the principles of the present invention may be formed;

FIG. 2 is a partial, side elevational view of a squared carton formed from the blank of FIG. 1, and showing the end flaps outfolded into a horizontal plane; and,

FIG. 3 is a fragmentary, perspective view of a par tially erected carton embodying the invention, and showing the sealing membrane applied thereto.

Referring to the drawings in which like reference characters refer to like parts throughout the several views thereof, a carton blank generally designated as cifically illustrated, it should be understood that the blank is symmetrical and the bottom portion is a mirror image of the top portion shown. In FIG. 1, consecutively articulated wall panels 12 are shown, together with glue panel 14, articulated to one another along vertical, parallel score lines 16, the length of which determines the final carton height.

As is conventional in blanks for this type of carton, wall panels 12 have end closing flaps articulated thereto along horizontal score line 30. It should be understood that although some of the panels are wider than others for forming a carton rectangular in crosssection, panels 12 could be of equal width in order to have a square carton. The end closing flaps are comprised of alternating major flaps 18 and dust flaps 20, as well as glue flap 22. The unillustrated bottom portion of blank 10 includes the identical structure, as should be understood.

As described thus far, blank 10 is in all respects conventional and similar to end sealed carton blanks known to the art. Blank 10 departs from conventional blanks in the configuration of the carton-forming structure. For example, score line 30 is interrupted in the areas immediately adjacent where score line 30 would intersect with vertical score lines 16. In these areas, pairs of diagonal score lines 32 are disposed, the axes of which intersect at point 34, which also is in the axis of the adjacent score line 16. Whereas, the angles formed by the angled score lines 32 with respect to the axis of score line 30 will vary depending upon the size of the carton, and the length of the angled score lines 32 will vary in the same manner, it has been found satisfactory in accordance herewith if the angle of the angled score lines 32 with the axis of score line 30 is around and the distance between point 34 and the axis of score line 30 is about 1/32 inch. With such an arrangement, small additions or appendages 33 form a part of wall panels 12.

Also, as can be seen in FIG. 1, the side edges of dust flaps 20 are tapered, with edges 24 ending in curved portions 26, which intersect the adjacent vertical side edges 27 of major end flaps 18 substantially at right angles. From this intersection point, cuts 28 extend toward points 34, but do not intersect such points, as shown in FIG. 1.

A drumhead carton embodying the improved corner construction, in accordance herewith, may be erected and sealed by known, well-accepted techniques. For example, a flattened carton tube may be formed by folding blankand adhesively securing glue panel 14 to the last wall panel 12 at the opposite end of blank 10. Thereafter, the tube, in its flattened form, may be shipped to the site of the carton filling, where it is then squared. A first end closure is then completed by first outfolding the flaps 18 and 20 into a horizontal plane (as indicated in FIG. 3). In doing so, the additions 33 of the wall panels form raised areas or lands ending at points 34, extending above the plane through the horizontally disposed end flaps, as is shown in FIG. 2.

In FIG. 2, erecting machine flights 36 are shown engaging the bottom surface of flaps 20 for holding them in place for application of sealing membrane 40, as shown in FIG. 3. Because cuts 28 do not extend entirely to points 34 when the end flaps are outfolded, as shown in FIG. 3, there is a tendency for the adjoining pairs of additions 33 to wall panels 12 to be forced at point 34 into a slightly outwardly curved configuration. With such an arrangement, upon pressure application of sealing membrane 40 to areas 42 on the surface of the various end flaps immediately adjacent and circumferentially around the opening of the carton, there is a slight upwardly directed resilient action in the contact areas 44 engaging membrane 40 (FIG. 3). Because of this upwardly directed resilient engagement with membrane 40, there is enhanced sealing in the corners of a sealed carton produced, in accordance herewith. When the end flaps are subsequently folded, therefore, the arrangements in accordance with this invention reduce substantially the occurrence of failure at the comers of the carton, particularly during subsequent distribution and handling procedures.

Accordingly, there is provided, in accordance herewith, an arrangement of an improved leak-proof corner structure for sealed cartons utilizing a separate membrane substance, heat sealed or otherwise adhesively secured to the outfolded end flaps of the erected carton. Because of the utilization of engaging surfaces at the corners thereof for application of the membrane, the engaging surfaces are substantially upwardly extending and resilient for increased sealing engagement with the membrane. Because the arrangements herein provide a substantial reduction in subsequent failure in the sealing cartons, the arrangements herein are highly advantageous commercially.

While the methods and apparatus herein disclosed form preferred embodiments of this invention, this invention is not limited to those specific methods and arrangements, and changes can be made therein without departing from the scope of this invention, which is defined in the appended claims.

What is claimed is:

l. A drumhead carton fabricated from paperboard sheet material and having four wall panels and a glue panel consecutively articulated to each other along four parallel vertical hinges, and alternating tapered dust flaps and major flaps articulated on each end of said wall panels and glue panel along hinge lines disposed in a single horizontal axis, the intersections of the axes of said vertical hinges with said axis of said horizontal hinges defining the comers of said carton; the combination which comprises said horizontal hinges terminating prior to said intersections; a pair of angled hinges disposed at each of said intersections, one each of each pair extending at an angle from said horizontal axis into the adjacent respective flap to a point in'the axis of the adjacent vertical hinge; the axis of each angled hinge of a pair intersecting the axis of the other of said pair in said adjacent vertical axis; each of said pairs of angled hinges defining a pair of substantially triangulat-shaped additions to said wall panels articulated at the said adjacent respective vertical hinge, whereby said adjoining pairs of triangular-shaped additions form outwardly, extending slightly curved contact areas at each of said corners when said flaps are outfolded into a horizontal plane; and a sealing membrane bonded to the inner surface of all said horizontally extending flaps and said contactareas, said membrane engaging said contact areas with a resilient bonding action.

2. A carton as recited in claim 1, in which said major flaps have vertical side edges, with each one disposed in one of said vertical axes, and the tapered side edges of each of the adjacent alternating dust flaps intersect said vertical side edges; and which includes a cut extending from each of said edge intersections to a point spaced from the intersection of the adjacent pair of anbetween said angled hinges and said horizontal hinges is about 5.

4. A carton as recited in claim 1, in which the distance between the axis of said horizontal hinges and the intersection of the axes of each pair of angled hinges is about 1/32 inch.

5. In a one-piece paperboard blank for an end-fillable carton adapted to be end-sealed with a membrane, and having four wall panels and a glue flap panel consecutively articulated to each other along four parallel vertical source lines, and alternating tapered dust flaps and major flaps articulated to said wall panels and said glue flap along score lines in a single horizontal axis, the intersections of one each of said vertical score lines with said horizontal axis defining a corner of a carton to be erected from said blank; the combination which comprises said horizontal score lines terminating prior to said intersections; a pair of angled score lines disposed at each of said intersections, one each of each pair extending at an angle from one of said terminations into the adjacent respective flap to a point in the axis of the said adjacent respective vertical score line; the axis of each angled score line of a pair intersecting the axis of the other of said pair in said adjacent vertical axis; and each of said pairs of angled score lines defining a pair of substantially triangular-shaped additions to said wall panels articulated at said adjacent vertical score line.

6. A blank as recited in claim 5, in which said major flaps have vertical side edges with each one disposed in one of said vertical axes and the tapered side edges of each of the said adjacent alternating dust flaps intersect said vertical side edges; and which includes a cut extending from each of said edge intersections to a point spaced from the said intersection of the adjacent pair of angled score lines.

7. A blank as recited in claim 5, in which the angle between said angled score lines and said horizontal score lines is about 5.

8. A blank as recited in claim 5, in which the distance between the axis of said horizontal score lines and the intersection of the axes of each pair of angled score lines is about 1/32 inch. 

1. A drumhead carton fabricated from paperboard sheet material and having four wall panels and a glue panel consecutively articulated to each other along four parallel vertical hinges, and alternating tapered dust flaps and major flaps articulated on each end of said wall panels and glue panel along hinge lines disposed in a single horizontal axis, the intersections of the axes of said vertical hinges with said axis of said horizontal hinges defining the corners of said carton; the combination which comprises said horizontal hinges terminating prior to said intersections; a pair of angled hinges disposed at each of said intersections, one each of each pair extending at an angle from said horizontal axis into the adjacent respective flap to a point in the axis of the adjacent vertical hinge; the axis of each angled hinge of a pair intersecting the axis of the other of said pair in said adjacent vertical axis; each of said pairs of angled hinges defining a pair of substantially triangular-shaped additions to said wall panels articulated at the said adjacent respective vertical hinge, whereby said adjoining pairs of triangular-shaped additions form outwardly, extending slightly curved contact areas at each of said corners when said flaps are outfolded into a horizontal plane; and a sealing membrane bonded to the inner surface of all said horizontally extending flaps and said contact areas, said membrane engaging said contact areas with a resilient bonding action.
 2. A carton as recited in claim 1, in which said major flaps have vertical side edges, with each one disposed in one of said vertical axes, and the tapered side edges of each of the adjacent alternating dust flaps intersect said vertical side edges; and which includes a cut extending from each of said edge intersections to a point spaced from the intersection of the adjacent pair of angled hinges.
 3. A carton as recited in claim 1, in which the angle between said angled hinges and said horizontal hinges is about 5*.
 4. A carton as recited in claim 1, in which the distance between the axis of said horizontal hinges and the intersection of the axes of each pair of angled hinges is about 1/32 inch.
 5. In a one-piece paperboard blank for an end-fillable carton adapted to be end-sealed with a membrane, and having four wall panels and a glue flap panel consecutively articulated to each other along four parallel vertical source lines, and alternating tapered dust flaps and major flaps articulated to said wall panels and said glue flap along score lines in a single horizontal axis, the intersections of one each of said vertical score lines with said horizontal axis defining a corner of a carton to be erected frOm said blank; the combination which comprises said horizontal score lines terminating prior to said intersections; a pair of angled score lines disposed at each of said intersections, one each of each pair extending at an angle from one of said terminations into the adjacent respective flap to a point in the axis of the said adjacent respective vertical score line; the axis of each angled score line of a pair intersecting the axis of the other of said pair in said adjacent vertical axis; and each of said pairs of angled score lines defining a pair of substantially triangular-shaped additions to said wall panels articulated at said adjacent vertical score line.
 6. A blank as recited in claim 5, in which said major flaps have vertical side edges with each one disposed in one of said vertical axes and the tapered side edges of each of the said adjacent alternating dust flaps intersect said vertical side edges; and which includes a cut extending from each of said edge intersections to a point spaced from the said intersection of the adjacent pair of angled score lines.
 7. A blank as recited in claim 5, in which the angle between said angled score lines and said horizontal score lines is about 5*.
 8. A blank as recited in claim 5, in which the distance between the axis of said horizontal score lines and the intersection of the axes of each pair of angled score lines is about 1/32 inch. 